SODA. 259 



The soft soap used in Great Britain is made with 

 potash in combination with animal oil ; but this alkali 

 cannot be employed in the manufacture of hard soap, 

 as by exposure to the air in damp weather, the soap 

 thus made would become soft and unsaleable, in 

 consequence of the moisture the potash would imbibe 

 from the air. 



Silex is found to fuse with more facility by the 

 action of soda than potash, producing likewise a 

 glass of greater hardness ; soda is therefore gene- 



Prickly Salt-wort < Salsola halt. 



